diff mbox

Speedup WPA on libreoffice

Message ID 20150119203702.GB23365@kam.mff.cuni.cz
State New
Headers show

Commit Message

Jan Hubicka Jan. 19, 2015, 8:37 p.m. UTC 
Hi,
libreoffice WPA gets somewhat slower compared to 4.8 because of more work we do
analyzing polymorphic call.  Many of these calls don't need analyzis because we will
not derive anything useful anyway. In this case it is a win to simply drop the info.

Bootstrapped/regtested x86_64-linux, comitted.
diff mbox

Patch

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 219857)
+++ ChangeLog	(working copy)
@@ -1,3 +1,8 @@ 
+2015-01-19  Jan Hubicka  <hubicka@ucw.cz>
+
+	* ipa-devirt.c (ipa_devirt): Drop polymorphic call info in hopeless
+	cases.
+
 2015-01-19  Vladimir Makarov  <vmakarov@redhat.com>
 
 	PR rtl-optimization/64671
Index: ipa-devirt.c
===================================================================
--- ipa-devirt.c	(revision 219826)
+++ ipa-devirt.c	(working copy)
@@ -2815,6 +2815,7 @@  ipa_devirt (void)
   int npolymorphic = 0, nspeculated = 0, nconverted = 0, ncold = 0;
   int nmultiple = 0, noverwritable = 0, ndevirtualized = 0, nnotdefined = 0;
   int nwrong = 0, nok = 0, nexternal = 0, nartificial = 0;
+  int ndropped = 0;
 
   if (!odr_types_ptr)
     return 0;
@@ -2865,6 +2866,28 @@  ipa_devirt (void)
 
 	    npolymorphic++;
 
+	    /* See if the call can be devirtualized by means of ipa-prop's
+	       polymorphic call context propagation.  If not, we can just
+	       forget about this call being polymorphic and avoid some heavy
+	       lifting in remove_unreachable_nodes that will otherwise try to
+	       keep all possible targets alive until inlining and in the inliner
+	       itself.
+
+	       This may need to be revisited once we add further ways to use
+	       the may edges, but it is a resonable thing to do right now.  */
+
+	    if ((e->indirect_info->param_index == -1
+		|| (!opt_for_fn (n->decl, flag_devirtualize_speculatively)
+		    && e->indirect_info->vptr_changed))
+		&& !flag_ltrans_devirtualize)
+	      {
+		e->indirect_info->polymorphic = false;
+		ndropped++;
+	        if (dump_file)
+		  fprintf (dump_file, "Dropping polymorphic call info;"
+			   " it can not be used by ipa-prop\n");
+	      }
+
 	    if (!opt_for_fn (n->decl, flag_devirtualize_speculatively))
 	      continue;
 
@@ -3094,11 +3117,11 @@  ipa_devirt (void)
 	     " %i speculatively devirtualized, %i cold\n"
 	     "%i have multiple targets, %i overwritable,"
 	     " %i already speculated (%i agree, %i disagree),"
-	     " %i external, %i not defined, %i artificial\n",
+	     " %i external, %i not defined, %i artificial, %i infos dropped\n",
 	     npolymorphic, ndevirtualized, nconverted, ncold,
 	     nmultiple, noverwritable, nspeculated, nok, nwrong,
-	     nexternal, nnotdefined, nartificial);
-  return ndevirtualized ? TODO_remove_functions : 0;
+	     nexternal, nnotdefined, nartificial, ndropped);
+  return ndevirtualized || ndropped ? TODO_remove_functions : 0;
 }
 
 namespace {